This invention relates to a torsion spring assembly having a torsion spring which, when loaded torsionally, exerts a biasing force on a member associated with the spring. The invention more particularly relates to a torsion spring of the type which is defined by a plurality of helically wound coils and by two radially projecting end tangs, the spring being loaded torsionally when one of the end tangs is moved angularly relative to the other end tang.
While the spring assembly of the invention may be used in various applications, it is particularly suitable for use in effecting closure of the throttle valve of the throttle body or carburetor of an automotive internal combusion engine. Previous torsion springs which have been used for this purpose most usually comprise a conventional coiled spring telescoped rather loosely over a bushing on a shaft and having one end tang which is anchored and another end tang which is connected to the throttle valve actuator. Conventional torsion springs of this type experience excessive coil cant and friction, produce an axial and radial sawing action and cause excessive wear of the bushing and the shaft.